What are your thoughts on hip dysplasia? Genetics, feeding, exercise or other please?

Believe it to be a combination problem, born with the tendency which is added to by exercise and may be feeding. Other things like being Kept in a cage for long periods or a too small a cage may also help to cause problems.

Genetics must be the most important factor as HD is virtually unknown in a lot of sighthound breeds, despite all the things that new owners do 'wrong' - over exercise, jumping, poor feeding etc

I'm with Chaumsong, Genetics.  We got a very badly bred pup(mother and son mating) and found out at 5 months that he had very severe HD.  We had fed him a high quality diet and he had no accidents or injuries and we had exercised him on soft surfaces moderately to fit in with his age recomendation.  I am sure nothing we did could've contributed to HD.  It must have been genetic.

On the other hand, some pups are over-exercised but then within the working community, that's perfectly acceptable.  Pups start training early and when they are in the field, it's an all day thing. 

Yes all of the above... I've seen pups born with good hips completely ruined by over exercise (very severe mind).  Environment - stairs, jumping in and out of cars can have their impact.  Food - too good a diet as well as a poor diet can have an effect.  Early neutering can 'cause' or lead to HD too :-(  If one side is affected it can be an injury or simply a problem birth - which may well not even have been noticed.. being stood on as a pup (by mum) can also lead to this...

Agree a lot of it can be due to genetics if all dogs were hipscored before breeding it would help.
I,ve just been looking at a dog who I am interested in but there is no true reflection of what he is producing as of the nine litters and sixty three puppies he has so far produced only one dogs results have been published so I,ve no idea what to expect from him so I,ll look elsewhere.

> of the nine litters and sixty three puppies he has so far produced only one dogs results have been published so I,ve no idea what to expect from him

Of course if everything in his pedigree is scored and there is a consistent pattern of acceptable scores there would be very little likelihood of issues. 

HD is inherited to a large extent but not in a simple fashion, so the more info you have on his relatives especially many generations then you have more chance of good results compared to say a dog who has a good score but no history of scoring in the pedigree.

With the high cost of hip scoring it may be years before a stud dog has many offspring scored as it will generally only those who are hoped to be bred from or who are to undertake soem strenuous activity.

Yes Barbara I agree its expensive but I.ve always had mine scored so that I know for myself even if I have no intention of breeding from them .

Researched this a lot as one of mine has HD.  It is essentially hereditary as dog has to be born dysplastic for the disease to occur.  It can be aggrevated by poor diet, over-exercise, injury etc but these things on their own can't cause Hip Dysplasia.

My dog comes from parents with good scores but there are a lot of dogs further back in the lines that were either not scored or their scores not disclosed so having parents with good scores doesn't necessarily mean their off-spring will be OK.

I actually don't agree with this and have seen a very damaged dog who comes from a long line of HD free dogs - severe over exercise and strain of the joints very young created an HD like condition.... of course HD can be passed on through good scoring dogs, but no other pup from this line has suffered... there are more causes to HD than 'merely' genetic unfortunately.

The polycentric nature of HD genes makes it impossible to tell where it will come out - and of course further down the lines can be before hip scores were thought of...

This is only one of the many articles I found.  I also found several books that referred to HD being a genetic condition.  If there is other research to the contrary I stand corrected but so far I didn't find any.

http://www.woodhavenlabs.com/chd.html

Further down the lines meant grandparents and great grandparents in this instance rather than pre hip-scoring records.

> I.ve always had mine scored so that I know for myself

Very few owners will do so, as after all for them it changes nothing, they have the dog they have.

Looking at 5 year rolling mean scores etc as in the charts in the two Kennel club health reports shows that hips are gradually improving through time (except in breeds with very low scores anyway).  So scoring (and obviously selecting against poor scores) over generations does lead to overall hip improvement.

it's one of those 'conditions' where it's easy to say 'its genetic' but not all causes of HD actually ARE genetic... unfortunately it's more complex than that :-(

I.ve always had mine scored so that I know for myself even if I have no intention of breeding from them .

I would not put my dogs through a General/A unless it was ab nessisary.

Some would say if you are breeding or if you have a breed where the average of over 10 then it is necessary.

I.ve always had mine scored so that I know for myself even if I have no intention of breeding from them .

Yes I agree Nova, but as you will see i was commenting on a post where the poster said even if I have no intention of breeding from them.

It's one of those 'conditions' where it's easy to say 'it's genetic' but not all causes of HD actually ARE genetic...

But surely it must be a chief point (essentially) or why would breeders, as has already been said on this thread, pay for (and put their dogs through) a General Anasthetic to have their dogs hips x-rayed, incurr a further cost to have them assessed by the BVA and then have them recorded at the KC to that other breeders can 'select' a dog with good hip scores to breed with?

Also, if over a period of time of breeders hip scoring, recording and carefully selecting dogs with low scores when breeding, the hip scores of many breed has improved, doesn't this indicate that genetics play an 'essential' part, otherwise whats the point?  You may as well breed any un-scored dog to any un-scored dog and see what 'accidentally' happens to hips of the off-spring.

Isn't the 'complexity' part  the fact  that pups can seem fine although they're born dysplastic. If their diet while developing is good and they do not over-exercise or have injuries then they live out their lives without any outward signs of the disease, and no-one would know unless they're hip scored. Whereas another pup born dysplastic might not have the same environmental influenses and so develop the disease?

This is all the evidence that I found and was indicated by vets, physios and surgeons when my dog was diagnosed.

because genetics is ONE cause of HD and it's important that dogs are sound from a genetics point of view.... just because genetics is an important cause of HD doesn't mean that it's the ONLY cause of HD :-( it's also vitally important that we don't lose sight of other effects and thus may lose good lines of dogs by simply assuming everything is caused by genetics.

Additionally due to the polycentric nature of HD you can have a long line of good hipped dogs and then you introduce another line of good hipped dogs and you merge the genes necessary to create HD in a litter... this doesn't mean the parents should never be used again, but it indicates that those particular genes shouldn't be mixed... until and unless we can identify the genes and how they work together (it's apparent that genes behave differently depending on the other genes present) we shouldn't simply say 'that dog has bred HD puppies so shouldn't be used again' - throwing the baby out with the bathwater and needlessly reducing the gene pool.

by the way, my dogs don't actually have a GA they get x-rayed under sedation....

Additionally due to the polycentric nature of HD you can have a long line of good hipped dogs and then you introduce another line of good hipped dogs and you merge the genes necessary to create HD in a litter... this doesn't mean the parents should never be used again, but it indicates that those particular genes shouldn't be mixed... until and unless we can identify the genes and how they work together (it's apparent that genes behave differently depending on the other genes present) we shouldn't simply say 'that dog has bred HD puppies so shouldn't be used again'

Which again shows that this hereditary, polygenic condition is down to genes.

As I said earlier, this is 'essentially', (not exclusive) a genetical problem.

this is 'essentially', (not exclusive) a genetical problem.

thanks for conceding the point, I have never said otherwise... but it's critical not to lose sight of the fact that HD is caused by a number of factors, an important one being genetics, but the other factors are also important.  It is also important to hip score and to watch what happens when outcross lines are put together, as this is when you can get more variety of genes and hence more of the HD genes can come together... it's important not to 'blame' the dogs or the breeder when there is no way of knowing... but it's also important to study the genetics behind the dogs and share information so more is known about what lines to put together and what lines not to put together....

it's also essential that owners treat their dogs with respect and give their hips a chance - then if there is a predisposition, they'll stay healthy and if there isn't their hips wont be damaged by - early neutering, inappropriate diet (too high or low in nutrients, too much calcium etc) too much stress on joints (stairs, jumping in and out of cars) and jumping/contact training in agility dogs.

There are studies which have connected these issues (and I've had personal experience of the last one!) and whilst it's impossible (which is a lot of the problem) to identify exactly what's hereditary and what's environmental there are studies which indicate all of these are causal factors.

although it doesn't say which study - here is a link about HD and early neutering
http://www.caninesports.com/SpayNeuter.html

this is 'essentially', (not exclusive) a genetical problem.

thanks for conceding the point,

I haven't conceded the point.  I always referred to this being 'essentially' a genetic issue whereas you stated it is not only a genetic .  I have merely clarified what 'essentially' actually means. 

In my case, the pup came with lameness which was suspected (by vets) as HD and monitored throughout development.  It  was not confirmed until some months later following x-rays done under GA.

Mmmm moving from

This is only one of the many articles I found.  I also found several books that referred to HD being a genetic condition.  If there is other research to the contrary I stand corrected but so far I didn't find any.

to
this is 'essentially', (not exclusive) a genetical problem.


appears to be some form of concession to me :-(

whereas I have always stated that the causes of HD are many, including genetic, environment and human interference (exercise/stairs/feeding & early neutering are examples) however, as long as we're agreed that genetic causes aren't the only cause of HD then I'm happy :-)

appears to be some form of concession to me

whereas I have always stated that the causes of HD are many, including genetic, environment and human interference (exercise/stairs/feeding & early neutering are examples) however, as long as we're agreed that genetic causes aren't the only cause of HD then I'm happy

Not at all.  I firmly believe that the essence of HD is genetic but it is not exclusive simply because it is /and can be aggrevated by environmental factors which include diet, exercise and inujury etc. 

I believe many dogs are dysplastic at birth  but it is so mild that it is not apparant unless and until some other environmental factor is applied.  Sometimes it's not apparant until much later in life but  I have found, in many books and on many veterinarian based websites like the one I posted the link to, confirmation that HD is a polygenic, hereditary disease.  I'm sorry if that doesn't make you happy but then we will just have to disagree as we have come to our own, if different, viewpoint on this subject.

Ok so I'm not happy, but also it doesn't worry me that you will not consider anything other than genetics to be the cause of HD - I'm sure you will realise that you need to be more open minded at some point. Unfortunately a lot of people appear to have closed minds where it comes to HD :-(

Of course much of HD is genetic, but not all of it.

The nature of HD is that it is a degenerative disease, so of course it will be present at birth and will show to a greater or lesser extent as the dog grows older.... it's interesting that in some dogs this happens and in others (even treated the same) it doesn't.  Some dogs have incredibly bad hips but remain active and pain free, only indication being the hip x-ray

Other dogs are born with good hips and environment, food, exercise, early neutering create HD.  I've seen it in a young dog whose joints were put under intense and severe stress.

It is clear to me that whilst HD is basically a genetic condition, there are other factors and dogs with good hips will suffer from HD for reasons other than genetics... as the genetics of HD are understood better this will become apparent.  Studies (eg on influence of early neutering and HD) are already indicating this.
However, that's it from me.

I'm sure you will realise that you need to be more open minded at some point. Unfortunately a lot of people appear to have closed minds where it comes to HD

What a shame you feel the need to make such offensive points as that above.

I just quickly did a search on Hip Dysplasia and the first half dozen sites that came up all state that HD in dogs is an hereditary, genetic condition including the bva's.  If I'm closed minded perhaps that's because all the research/evidence reinforces the information I've been given by other medical professionals.

http://www.medicinenet.com/pets/dog-health/hip_dysplasia_causes_and_symptoms_in_dogs.htm

http://www.peteducation.com/article.cfm?c=2+2084&aid=444

http://pets.webmd.com/dogs/hip-dysplasia-dogs-causes-symptoms-tests

http://en.wikipedia.org/wiki/Hip_dysplasia_(canine)

http://www.bva.co.uk/public/documents/Hip_Dysplasia.pdf

> I believe many dogs are dysplastic at birth  but it is so mild that it is not apparant unless and until some other environmental factor is applied

Most displastic dogs have normal hips at birth (as confirmed in one of the links you put up), hip displasia is a developmental problem.

It is possible to hipscore a dog without a general anaesthetic and surely its up to the individual owner if they want to score their dog.
Surely its better to score than have your head stuck in the sand and ignore the high levels of hip dysplacia in some breeds.
Normally when I get to this stage I will delete my answer but just now and again I would like to join this forum and enter into a discussion without it turning into a free for all and ending up in the topic being locked.
Without  a proper hip scoring system it would in my opinion be very difficult to determine if hip dysplacia is due to genetics feeding upbringing or anything else.
Surely anyhing that helps to breed healthy dogs can only be good.

It is possible to hipscore a dog without a general anaesthetic

yes it can be done under sedation :-)

http://www.hipdysplasiaindogs.com/hip-dysplasia-in-dogs-causes.html

When it comes to hip dysplasia, veterinarians and animal health experts are not quite sure what really causes the disease. The main root of the problem is still under research and scrutiny, although there are some definite reasons why hip dysplasia occurs in canines.

The other known cause of hip dysplasia in dogs is improper nutrition. Pet owners who fail to feed their dogs with the food that is a match to their body requirements tend to become obese. Obesity causes the legs to deform.

This is true with both animals and humans. With all of the extra body weight to support, the hip's ball and socket joints tend to grow apart, causing hip dysplasia. This condition may also give rise to a very similar disease, which is canine arthritis. Proper feeding is very important, especially with dogs of the larger breeds.

If your pet has lowered calcium and protein levels, hip dysplasia may also occur. Calcium, as you know, is the main component of the bones. Without calcium, the bones will get weaker and become prone to deformation and breakage. When the hip bones get distorted, hip dysplasia may possibly occur.

The same is true in the case of protein. Protein is the building blocks of muscles. Strong and firm muscles can keep the hip joints intact. If they become loose and saggy, the hip joints get affected. This then becomes the reason why hip dysplasia develops in some dogs.

Dogs suffering from hip dysplasia caused by protein and calcium deficiencies can easily be treated by giving them the required daily allowances of these nutrients. By feeding your pet with a high protein and calcium foods, you are actually helping combat the disease. There are also dog supplements that you can use to further strengthen its defenses against the disease.

On the other hand, some dogs acquire hip dysplasia due to too much exercise. There are dog breeds that are built for certain jobs, such as sled running. Some dogs, especially the mixed breeds, have muscles or bones that are not as strong, and their masters force them to do manual labor. Such dogs are more prone to developing hip dysplasia because of the intense exercise load and the strains that their legs have to go through every day.

These are some of the causes of canine hip dysplasia. Be sure that you keep your dog away from these factors, whenever possible, to reduce its risks of acquiring the disease.

http://www.ideamarketers.com/?Causes_Of_Hip_Dysplasia_In_Dogs&articleid=801918

The main Causes of Hip Dysplasia in dogs are considered transmissible, but according to the new researches conclusively suggest that environment also play a role in this cause. The environment influence would include. * Overweight condition. * Injury at young age. * Ligament tears at young age. * Repetitive motion on forming joint. Etc...

Main Reasons to Causes of Hip Dysplasia in Dogs is due to Genetics, Improper nutrition and lowered Calcium and protein levels. . Primarily Genetics play a very crucial role in the development of both animals and humans. The condition of the parent determines the type of offspring born. Therefore when ever the dog which is suffering from hip dysplasia produces puppies, it is more chances of acquiring that disease to puppies.

Secondly the Causes of Hip Dysplasia in Dogs is caused due to the improper nutrition. The dog owners are not able to feed sufficient nutrition food to the dogs, so that the legs are deformed and severe pain is born in the leg hips this disease is called Hip Dysplasia.

Tertially the dog is lowered calcium and protein levels, as you know that the bone is the main component of our body. Without calcium, the bones will get weaker and become prone to deformation and breakage. When the bones get distorts, hip dysplasia may possibly occur. Similarly proteins are building blocks of muscles. Strong muscles can keep the hip joint intact. If they become loose, the hip joints get affected; this is also a main reason to affecting hip dysplasia in dogs.

There is another ways to Causes of Hip Dysplasia in Dogs are some dogs acquire hip dysplasia due to too much exercise. Some dogs, especially the mixed breeds, have muscles or bones that are not as strong, such dogs are highly affected to hip dysplasia.

The Causes of Hip Dysplasia in Dogs is most commonly appeared when the dog at a age of 18 months. Richard Pitcairn States that the hip of the young dogs are weakened by heavy vaccination. 

http://www.acvs.org/AnimalOwners/HealthConditions/SmallAnimalTopics/HipDysplasiainDogs/

Causes
Causes of hip dysplasia are considered to be multifactorial; including both hereditary and environmental factors.  Rapid weight gain and growth through excessive nutritional intake may encourage the development of hip dysplasia.  Mild repeated trauma causing synovial (joint lining) inflammation may also be important.

http://rdelp.hubpages.com/hub/Hip-Dysplasia-in-dogs-Causes-Prevention-and-Treatment

Causes

The two most common cause of hip dysplasia in dogs are hereditary and nutritional. Dogs who have hip dysplasia are more apt to pass this condition on to their puppies than those who do not. The puppy may then simply be a carrier or may suffer for the disease itself. Poor nutrition may also lead to the development of this disease in dogs who otherwise would be healthy.

Most displastic dogs have normal hips at birth (as confirmed in one of the links you put up), hip displasia is a developmental problem.

I'm not sure which article you are referring to but here are some direct quotes:

' researchers agree that hip dysplasia is a genetic disease.  If a parent has HD then the animal's off-spring are at greater risk for developing HD.  If there are no carriers of HD in a dog's lineage then its highly unlikely he will contract the disease.  If there are genetic carriers then he may.'

'while there is much we don't know we do know that canine hip dysplasia is a genetically transmitted diesease.  If you need to, or disagree at this point, please re-read that statement.  ...... The genetic concept of heritability is a complicating factor and is one reason why HD remains contraversial'.

'most importantly hip dysplasia is genetically inheritable and is polygenic and multifactorial.  In short, you can get it in your breeding programme when you bred from animals that did not show it.'

'Hip dyslasia is not something a dog acquires, a dog is either genetically dysplastic  (Oxford Dictionary Def: abnormal growth of tissues) or it is not. Initially, the hips of affected and normal puppies are indistinguishable.  Later in life, an affected animal can exhibit a wide range of phenotypes from normal to severely dysplastic and functionally crippled.  You should take away from this article the idea that HD is genetically inherited'.

'HD is a particular hereditary problem.  But the way it is passed on makes it difficult to eradicate it: it is difficult to distinguish between dogs that carry the genes but whose environment has been sufficiently controlled to reduce the visible expression of the disease, from 'healthy carriers' who carry part of the genes and those individuals that are completely free from it.

If you read the last couple of quotes they  state you can't tell the difference between those puppies that are affected and those that aren't.  But, if those that are are then subjected to other environmental influences such as diet, exercise etc then you will see HD.

It is hereditary and quite clearly some dogs are 'carriers' and never give any indication that  they have the disease but they most probably would if subjected to the 'right' environmental factors that influence the disease.

If you have a problem with anything the articles state then the argument is with the writers not me.  I have merely shown some of the evidence I found which supported my original post and by which I stand. And certainly I am not closed minded or I wouldn't have gone to the trouble of researching all that I did when confronted with the disease.

All the paras in quotes '    ' above are directly from links/websites

One of the links didn't show up in my earlier post so here it is now

http://www.gsdfederation.co.za/articles/hip-dysplasia.htm

bottom of page 3 is the relevant section

julie t - is your question a theoretical research one or do you have some unanswered issues about your own dogs or are you looking at breeding?

It's an important topic, and a fascinating subject, but one which can easily get a bit bogged down (as you can no doubt see!!), however we can probably give you a bit more specific help if you want to redirect us with a slightly more focussed question.

I've had 2 dogs scored, I show them both, and did it as a 'favour' to the breed and breeder without any expectation of using either boy for breeding.  When choosing a puppy I want to know the parents scores and as many as I can see in the pedigree, as well as siblings scores.  My youngest dog comes from a litter of 11, 5 of whom have since been scored and all are well below breed mean score.  I take great care to manage diet and exercise to ensure I don't ruin well bred hips :)

Thank goodness dogs a babe a sensible post without the tedious attempts at point scoring.

The OP asked what people's thoughts were on this subject and if the cause was genetic, food, exercise etc. so it was inevitable that replies would centre around those issues.  

I found the answers and links very interesting reading on a very contraversial subject.

HD is virtually unknown in a lot of sighthound breeds

Find this an interesting statement can I ask which of the sighthounds you were thinking of.

PennyCG said Causes of hip dysplasia are considered to be multifactorial;

Definition of Multifactorial:

Multifactorial: In medicine, referring to multiple factors in heredity or disease. For example, traits and conditions that are caused by more than one gene occurring together are multifactorial, and diseases that are caused by more than one factor interacting (for example, heredity and diet in diabetes) are multifactorial.

I think some confusion seems to ocurr because some think that the genetic part and the environment part act independently of each other.

But from this and other definitions I've found it would appear that there are several genes that dictate if this disease is present or not and it is then INFLUENCED by environmental factors but the environmental factors alone can't CAUSE the condition but poor diet progresses the disease (peteducation website link).

Nova

Don't know what the person who mentioned sighthounds was referring to but having read all the links on this thread I note that the peteducation site does state that sighthounds such as greyhounds and borzoi have a very low incidence rate of the disease.

Does the HD screening result vary depending of the age of the dog?

It may be me, and I certainly don't want anyone to think I 'point score' because I don't have that intention, just a desire to put my view across, which I'll only do if I actually know something about a topic, but I don't think I've ever said (I've had a quick look through my postings and can't find it)  Causes of hip dysplasia are considered to be multifactorial; - it may appear in one of the quotes, although of course they're not my words (they're quoted from the reference given above them) - although I have said in various ways that there are multiple causes of HD, one of which is genetics.....

so I'd rather my views weren't distilled to a definition of a term

My understanding of HD is that there are a number of causes... and that HD can be made worse by a number of factors, not all of which are understood.

Much of HD is clearly genetic, but it's important to realise that it is polygenic in nature, created by a number of genes coming together, genes which react differently depending on which other genes are present making it difficult (impossible up to now) to find a DNA test for HD.  The best we're likely to come up with is a range of genes which shouldn't be included together in one mating.

environmental factors can make a congenital condition worse.  This includes exercise, food, early neutering etc.  It can also be caused by injury, during birth or shortly after. There may be other congenital problems which lead to HD - eg malformation of pelvic bones...

It is also clear that environmental factors can create the conditions necessary for HD to develop. 

It is clearly important to hip score and to be aware of differing lines which may carry differing genes and not to lay blame if HD occurs when health tests etc are carried out, we know that this can happen.  We should also be careful when bringing up puppies, how we exercise them, stairs etc, how we feed them, when we neuter them etc

Does the HD screening result vary depending of the age of the dog?

Yes, very much so.  It's a good idea to ignore the 12 month rule if you have a big slow maturing breed and waiting for your dog to be fully mature before you have him hipscored.  As the dog grows the angles of joints and bones can vary (even minutely) which may have an influence on the score.  Smaller breeds are likely to mature by the 12 months, but it's worth making an individual assessment.  It can also be affected by leaving it too long - so wear and tear which may be normal in an older dog would be scored... having an injury would also impact on the scoring.

Whilst I didn't actually have him scored, my (now) eldest collie was xrayed a couple of years ago, aged about 7 due to a mysterious intermittent lameness he had, the vet said his hips were wonderful, which was good to know.

It is possible, of course, that we should have our dogs re scored at an older age - because there are some thoughts that degeneration may occur later than the usual time for scoring at 12-24 months and we should be aware of those dogs whose hips remain strong throughout life and which don't.  However, clearly environmental factors will have more of an effect, although if people believe that sound hips wont be adversely affected then there's no reason to think that a 5 or 7 year old dogs hips will be more affected than a 12 month old dog.  All interesting stuff.

Nova

Don't know what the person who mentioned sighthounds was referring to but having read all the links on this thread I note that the peteducation site does state that sighthounds such as greyhounds and borzoi have a very low incidence rate of the disease.

It was chaumsong and I was surprised because so few sighthounds bother to score their hounds so I wondered how the state of the hips were known. The presents of poor hips does not always show in poor movement although with sighthounds there are some with very poor movements so I was wondering where the information came from. A few Afghans have been scored and there mean is 11 and the range 0 to 54 good but on a par with the best of other breeds but only 48 have been scored. The Ridgebacks are the only non-scent hounds who score and they have a mean of 8 and a range of 0 to 88.

The two breeds that have bothered to score are good but there is know way to know the incidence from such low numbers.

Just tagging on at the end, but I was interested to read that swaddling seems to be a cause of HD in babies. So it seems clear that environment is a major influence.

swaddling seems to be a cause of HD in babies

Would think that any interference with the soft and growing joints would have an effect which is why I said born with a tendency that can be helped or hindered by husbandry.

Hi dogs a babe
It's a worry, I have two breeds both pre disposed to hip displasia , fed on top quality food, but have also heard that high protein puppy food can cause rapid growth, joint,probs etc, as far as I can I keep to the five min rule, however occasionally have run over the times but not often, my pups play and play fight with each other and are generally boisterous happy pups . I will be showing them and would like to breed in the future so obviously I would like to hear ppl's views, my vet says inherited, my breeder says 27% inherited the rest due to over exercise etc, and wat do you call over exercise? 5 mins walking, fifteen mins running, daily, weekly, occasionally?  So really just wanted to air the question as I am open to interpretation

A period of time of breeders hip scoring, recording and carefully selecting dogs with low scores when breeding, the hip scores of many breed has improved. It doesn't show this indicate that genetics perform necessary part, otherwise whats the point.

A period of time of breeders hip scoring, recording and carefully selecting dogs with low scores when breeding, the hip scores of many breed has improved. It doesn't show this indicate that genetics perform necessary part, otherwise whats the point.

That's exactly the point I made earlier in this thread. 

I found many research papers and spoke to vets, chiropractors, physios and surgeons when my dog was diagnosed so that I could select the best method of treating/managing the disease.  All said that the pup has to be dysplastic at birth for the diesease to emerge;  that this is genetic and hereditary but in some cases can be so mild that the dog seems unaffected until and unless it is subjected to other environmental influences such as poor diet, over-feeding, too much exercise etc.  But because the dog seems OK earlier on then diet, exercise etc is BLAMED for the HD but this isn't the case, the dog had to be genetically susceptible in the first place. 

I was also told that because it is hard to distinguish early on (in puppies) if HD is present or not then its a waste of time x-raying until at least 12 months old unless you use the Pennhip method which is done from approx. 4 months onwards.  But this method of diagnosis is extremely difficult to get as it requires specially trained people and is very expensive. The very fact that it is hard to distinguish in pups makes some people think it isn't present from birth and so blame factors other than genetics for the later emergence of the disease.

Dogs with mild HD and good environmental influences can go through life showing no outward signs of the disease at all but they are carriers and if bred with another carrier/suffer will produce HD in their off-spring.  Some dogs of course are totally free of the disease.

Over exercise as pups in large/heavy can cause joint/mobility problems later in life because the growth plates have not fully formed or matured at the time but these joint probs are not necessarily related to HD.

I did read the canine sports productions link which PennyGC put up.  It discusses the many adverse effects of early neutering and mentions that a higher incidence rate of HD appeared in early neutered dogs.  It doesn't say anything about whether these dogs were genetically carriers/suffers anyway so seems irrelevant.  In fact genetics didn't feature in this article at all so were the dogs genetically tested for HD?  Might they be carrying/suffering from the HD gene anyway and the early neutering influenced the emergence rather than early neutering be the cause??